Well yes, but I mean people can complain by saying 'spammer' or 'links to trojans' or something, not many people are gonna leave a comment saying 'I like this post'.
Comments should be optional really, I'm happy to add one if necessary but mostly I would vote if people had been helpful and informative, etc., and I'm not gonna bother typing out that they were each time.
Edit/off-topic: 3333 posts, guido